CX74063

• Direct down-conversion receiver eliminates the image reject/IF filters
• Three separate LNAs with single-ended inputs
• RF gain range: GSM = 20 dB, DCS/PCS = 22 dB. Baseband gain range = 100 dB
• Gain selectable in 2 dB steps
• Integrated receive baseband filters with tunable bandwidth

The CX74063 transceiver is a highly integrated device for multiband Global System for Mobile Communications (GSM) or General Packet Radio Service (GPRS) applications. The device requires a minimal number of external components to complete a GSM radio subsystem. The CX74063 supports GSM850, EGSM900, DCS1800, and PCS1900 applications. The receiver also supports downlink Enhanced Data-Rate GSM Evolution (EDGE).

The receive path implements a direct down-conversion architecture that eliminates the need for Intermediate Frequency (IF) components. The CX74063 receiver consists of three integrated Low Noise Amplifiers (LNAs), a quadrature demodulator, tunable receiver baseband filters, and a DC-offset correction sequencer.

In the transmit path, CX74063 consists of an In-phase and Quadrature (I/Q) modulator within a frequency translation loop designed to perform frequency up-conversion with high output spectral purity. This loop also contains a phase-frequency detector, charge pump, mixer, programmable dividers, and high power transmit Voltage Controlled Oscillators (VCOs) with no external tank required. With the integrated gain controller (and an integrator ), the device realizes the Power Amplifier Control (PAC) functionality when combined with a coupler, a Radio Frequency (RF) detector and a Power Amplifier (PA).

The CX74063 also features an integrated, fully programmable, sigma-delta fractional-N synthesizer suitable for GPRS multi-slot operation. Except for the loop filter, the frequency synthesizer function, including a wideband VCO, is completely on-chip. The reference frequency for the synthesizer is supplied by the integrated crystal oscillator circuitry.

The CX74063 is available as a 56-pin RFLGA™ 8x8 mm package with either a circular ground pad or a four-quadrant ground pad. Package dimensions are shown in Figures 1 and 2.